<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>算术运算符</title>
</head>
<body>
<script>
  //1.当加法运算符的两边是数值是 是相加
  var n1 = 10 + 20;
  console.log(n1);
  //2.当两边为字符串 或者其中一个为字符串时 变成字符串拼接 结果是字符串
  var s1 = '10'+20;
  console.log(s1);
  //- * / %
  console.log(20 - 10);
  console.log(20 * 10);
  console.log(20 / 10);
  console.log(20 % 10);
</script>
</body>
</html>